1. Field of the Invention
This invention relates to novel peroxygen bleach activator compounds that aid in providing efficient peroxygen bleaching of fabrics over a wide temperature range when combined with a source of hydrogen peroxide in aqueous media. These compounds have the general structures: ##STR3##
wherein R is a straight or branched chain C.sub.1-20 alkyl, alkoxyl, cycloalkyl and mixtures thereof; R.sup.1 contains at least one carbon atom which is singly bonded directly to N; n is an integer from 1 to 6 and X is methylene or a heteroatom; or ##STR4##
wherein n is the same as in (I); but R.sup.2 contains a carbon atom doubly bonded directly to N, and, either X is a heteroatom, R is C.sub.4-17 alkyl or both.
2. Brief Statement on the Prior Art
It is well known that peroxygen bleaches are effective in removing stains and/or soils from textiles. They can be used on a wide variety of fabrics and colored garments. However the efficacy of peroxygen bleaches can vary greatly with temperature of the wash water in which they are used and they are usually most effective when the bleaching solution is above 130.degree. F. Below this temperature, it has been found that peroxide bleaching efficacy can be greatly increased by the simultaneous use of activators, otherwise known as peracid precursors. It has widely been accepted that in aqueous media, precursors and peroxygen combine to form peracid species. However, efficacy of most precursors, such as tetracetylethylene diamine (TAED), is also dependent on high wash water temperature. However, there is a need for bleach activator or peracid precursor compounds which are able to react with peroxide efficiently at low temperatures (70.degree.-100.degree. F.) to form peracids in good yields for proper cleaning performance.
Peracids themselves can be hazardous to make and are particularly prone to decomposition upon long-term storage. Thus it is advantageous to prepare the more stable peracid precursor compounds, which in alkaline water solution will react with peroxide anion to form the desired peracid in situ. As can be seen from the extensive literature in this area, many such peroxygen activators (peracid precursors) have been proposed. However, no reference appears to have taught, disclosed or suggested the advantages of leaving groups containing nitrogen in perhydrolysis.
Various compounds have been disclosed in the prior art that contain nitrogen as part of the leaving group of the peroxygen precursors. Murray, U.S. Pat. No. 3,969,257, Gray, U.S. Pat. No. 3,655,567, Baevsky, U.S. Pat. No. 3,061,550, and Murray, U.S. Pat. No. 3,928,223 appear to disclose the use of acyl groups attached to nitrogen atoms as leaving groups for activators. In all these examples, the acyl carbon atom is directly attached to the nitrogen atom. The nitrogen can in turn be attached to other carbonyl carbon groups.
In Finley et al, U.S. Pat. No. 4,164,395, a sulfonyl group is attached to the nitrogen atom of the leaving group. The activator structure is thus a sulfonyl oxime.
Dounchis et al, U.S. Pat. No. 3,975,153 teaches the use of only isophorone oxime acetate as a bleach activator. It is claimed that this isophorone derivative results in an activator of low odor and low toxicity. In Sarot et al, U.S. Pat. No. 3,816,319, the use of diacylated glyoximes are taught. The use is restricted to diacylated dialkylglyoximes wherein the alkyl group contains one to four carbon atoms and the acyl group contains two to four atoms. In neither reference is it disclosed, taught or suggested that it is surprisingly necessary to provide a heteroatom alpha to the carbonyl of the acyl group if a peracid precursor contains oxime as a leaving group. Additionally, neither reference discloses the unique advantages conferred by surface active peracid precursors which contain about 4-14 carbons in the acyl group.